Methane Cold Seeps As Biological Oases in the High‐
LIMNOLOGY and Limnol. Oceanogr. 00, 2017, 00–00 VC 2017 The Authors Limnology and Oceanography published by Wiley Periodicals, Inc. OCEANOGRAPHY on behalf of Association for the Sciences of Limnology and Oceanography doi: 10.1002/lno.10732 Methane cold seeps as biological oases in the high-Arctic deep sea Emmelie K. L. A˚ strom€ ,1* Michael L. Carroll,1,2 William G. Ambrose, Jr.,1,2,3,4 Arunima Sen,1 Anna Silyakova,1 JoLynn Carroll1,2 1CAGE - Centre for Arctic Gas Hydrate, Environment and Climate, Department of Geosciences, UiT The Arctic University of Norway, Tromsø, Norway 2Akvaplan-niva, FRAM – High North Research Centre for Climate and the Environment, Tromsø, Norway 3Division of Polar Programs, National Science Foundation, Arlington, Virginia 4Department of Biology, Bates College, Lewiston, Maine Abstract Cold seeps can support unique faunal communities via chemosynthetic interactions fueled by seabed emissions of hydrocarbons. Additionally, cold seeps can enhance habitat complexity at the deep seafloor through the accretion of methane derived authigenic carbonates (MDAC). We examined infaunal and mega- faunal community structure at high-Arctic cold seeps through analyses of benthic samples and seafloor pho- tographs from pockmarks exhibiting highly elevated methane concentrations in sediments and the water column at Vestnesa Ridge (VR), Svalbard (798 N). Infaunal biomass and abundance were five times higher, species richness was 2.5 times higher and diversity was 1.5 times higher at methane-rich Vestnesa compared to a nearby control region. Seabed photos reveal different faunal associations inside, at the edge, and outside Vestnesa pockmarks. Brittle stars were the most common megafauna occurring on the soft bottom plains out- side pockmarks.
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